The present invention relates generally to spare tire carriers, and more particularly to bumper mounted spare tire carriers suitable for very heavy tires, such as those used by off road vehicles and military vehicles.
For a variety of reasons, it is often desirable for a vehicle to be equipped with a spare tire. Indeed, the desirabilty and necessity of carrying a spare tire is well established. Spare tires are generally stowed in designated locations with regard to the specific type of vehicle. The spare tire in an automobile, for example, is conveniently located within the trunk or cargo compartment. In light trucks and derivative recreational and off-road vehicles, the spare tire is typically supported against the underside of the vehicle or the rear of the vehicle. Various placements of a spare tire are employed for motor homes and travel trailers.
Under-chassis placement on vehicles that are used for off road or cross-country travel, including military vehicles, is particularly problematic. The depending assemblage of tire and mount present an encumbrance that is readily snagged or caught upon brush, rocks, and other terrain obstacles, impeding progress and incurring damage to the vehicle. Interior storage space, on the other hand, is generally inconvenient and wasteful of precious cargo space.
Spare tire carriers for such vehicles have traditionally been mounted at the rear of the vehicle. U.S. Pat. No. 1,849,855 issued to F. A. Stutsman et. al. on Mar. 15, 1932, discloses a tire carrier mounted at the rear body portion of a vehicle and which comprises a stationary part and a swingable tire carrying part that can be lowered to the ground in order to remove the tire from the carrier. If a vehicle, however, is equipped with a tailgate or some other type of rear closure assembly such as a door, a rear mounted tire carrier such as that of Stutsman et al. will interfere with the operation of the closure assembly.
To overcome this difficulty, many conventional spare tire carriers have been mounted on a pivotable frame to allow the carrier to be swung away from the rear closure assembly. Such carriers have been mounted either on the vehicle body, the vehicle bumper, or a combination thereof.
A relatively simple yet well known unit incorporates a pair of angularly disposed arms. The free end of each arm is hingedly affixed to the body of the vehicle. An arrangement for detachably securing a spare tire is typically carried at the apex of the arms. Rotation of the device, between stowed or normal position and the door access position, is about a vertical axis. This configuration, however, has proven to be less than satisfactory. A primary deficiency is associated with the mounting upon the body. Vehicular body panels are commonly fabricated of relatively lightweight material. The combined mass of the carrier and the tire, constantly vibrating when the vehicle is underway, imparts stress and fatigue to the body panel resulting in eventual material failure.
One device mounted on a combination of the vehicle body and rear bumper is disclosed in U.S. Pat. No. 4,817,834, issued to Raymond C. Weiler on Apr. 4, 1989. This device is primarily supported by the rear bumper, rotates about a vertical axis between a stowed or normal position and an position which permits access to the rear closure assembly, and requires a body mounted latch for retaining the spare tire in the normal position. Considerable stress, however, is placed upon the latch as a result of the inherent instability of the pivotable attachment to the bumper.
A device mounted a rear vehicle bumper is disclosed in U.S. Pat. No. 4,679,717 to Hansen, issued on Jul. 14, 1987. This device is supported only by the rear vehicle bumper, rotates about a vertical axis between a stowed or normal position and a position which permits access to the rear closure assembly, and does not include a body mounted latch for securing the tire in the normal position.
In addition to not interfering with the tailgate or some other type of rear closure assembly, a problem to be overcome with spare tire carriers mounted on the rear of a vehicle is the need to lift the tire off of the carrier or to lift the tire onto the tire carrier. This is a particular difficulty with tires for off road and military vehicles, which tend to be four to five times heavier than tires for commercial vehicles. By way of example, one such military vehicle where this is of particular concern is the High Mobility Multipurpose Wheeled Vehicle (HMMWV or HumVee) manufactured by AM General. While there are a number of different HumVee models, a tire for a typical HumVee weighs approximately one hundred and twenty two (122) pounds and costs approximately US$800. HumVee tires may include a runflat system which permits the tire to be driven flat for twenty (20) miles at thirty miles per hour (30 mph) and a CTIS (Central Tire Inflation System) which allows the driver to inflate or deflate the tire on the move. Adjusting the tire pressure impacts the traction provided by the tire. Such options increase the weight and cost of a tire. The weight of these tires is of particular moment, given the US military""s guidelines which recommend the per person lift load be no greater than forty two (42) pounds. Under these guidelines, a minimum of three (3) people are needed to lift a spare tire. Because of the cost of each tire, it is preferred that any damaged tires which are replaced in the field be recovered for repair. The weight of the tires, however, and the need to lift the tire to the spare tire carrier inhibits such recovery.
U.S. Pat. No. 3,822,814, issued to Baldi on Jul. 9, 1974, discloses a bumper mounted spare tire carrier which addresses the difficulty of lifting a tire to the spare tire carrier. In this case, the spare tire carrier comprises a mounting bracket bolted to a rear bumper of a vehicle and the tire is attached to a rigid arm pivotally mounted at one end of the bracket. The arm extends beyond the attachment point of the tire and a handle is mounted at a distal end of the arm so that the tire can be lowed by grasping the handle, unlatching a latch and pivoting the arm and tire downwardly to the ground for easy removal or attachment of the tire.
Although the Baldi patent provides a tire carrier which allows operation of the rear closure assembly without interference and also permits the tire to swing downwardly to make mounting and removing the spare tire less burdensome, one has to swing the tire downwardly and afterwards upwardly every time one wishes to use the tailgate or other rear closure assembly of the vehicle to which the device of Baldi is attached. U.S. Pat. No. 5,186,371 to Jozeczak et al., issued on Feb. 16, 1993, discloses a spare tire carrier affixed to the body of the vehicle that allows the tire to swing downwardly for easy removal and which is adapted to swing from a latched position adjacent to the rear portion of the vehicle to an open position. The device of Jozeczak et al., however, requires a body mounted latch for retaining the spare tire in the normal position and suffers from the deficiencies discussed above of body mounted carriers and carriers which require a body mounted latch for retaining the spare tire in the normal position. Moreover, a tremendous amount of leverage is required to lift the tire above its center of gravity. Devices like the device of Jozeczak et al., however, require the tire to be lifted above its center of gravity because doing so results in a tire in a stowed position that is very stable without the need for a powerful locking mechanism as the weight of the tire acts to hold the tire in place.
For off road vehicles, and military vehicles in particular, the spare tire carriers disclosed in the art are not suitable. Simply put, these carriers are designed for on road use and cannot withstand the stresses and strains placed upon them when supporting a larger tire in an off road environment. By way of comparison, a tire for a passenger car typically measures approximately twenty seven (27) inches in diameter and has a tread width of approximately seven (7) inches. A tire for a HumVee, however, measures thirty seven (37) inches in diameter and has a tread width of twelve (12) inches. The strains and stresses associated with supporting such tires is great. For example, a HumVee is capable of scaling an eighteen (18) inch vertical wall, with approach and departure angles of seventy two degrees (72xc2x0) and thirty seven and one half degrees (37.5xc2x0). Operational considerations such as these render carriers of the type disclosed in the art unsuitable. Furthermore, the increased weight of the larger tire precludes the lifting of the tire required by the carriers of the type disclosed in the art. The HumVee provides at least sixteen (16) inches of ground clearance, and rides high off the ground. Indeed, spare tire carriers for the HumVee typically mount the spare tire approximately five (5) from the ground. Thus, those carriers disclosed in the art which require lifting of the tire and/or carrier are also particularly unsuitable for use on off road vehicles such as a HumVee.
Because of the unsuitability of the carriers in the art which address the lifting of the tire to/from the carrier, the disclosures of these references have not been implemented for military vehicles such as the HumVee and lifting of the tires mounted to the carrier is done through brute force. FIG. 1 shows a conventional spare tire carrier for the HumVee and its civilian counterpart (the Hummer) which is currently available from AM General. Plate 10, which includes two flanges having receptacles for receiving the carrier, is mounted to rear bumper 15 by bolts 20. Carrier 30 is inserted through the flanges of plate 10 at reference numeral 40. Thus, the carrier pivots about reference numeral 40. The carrier is secured from pivoting by latch 50, and the tire is mounted to the carrier at reference numeral 60. The ground clearance for a HumVee is typically thirty six (36) inches, and mounting point 60 is substantially higher, approximately sixty (60) inches from the ground.
One solution to the problem of lifting a tire to the carrier for a HumVee is shown at [http://]humvee.net/hid/tire/shoist.html. FIG. 2a shows the various parts of this hoist. FIG. 2b shows this hoist in operation. FIG. 2c shows the use of the tire carrier prop of this hoist to secure the carrier in the open position. FIG. 2d shows the inside of the tire carrier without the base of this hoist. There are, however, many drawbacks to such a hoist. Such drawbacks include the number of separate parts of the hoist, which are stored separately from the carrier when not in use, and that the hoist is not integral with the carrier. The need to separately store a number of individual parts for later assembly is not well suited for use in the off road environment, including the military environment.
In view of the foregoing, several needs have been recognized, among which is a need to provide a spare tire carrier capable of supporting the heavy tires used on off road vehicles, including military vehicles, and in which lifting of the tire is minimized.
In accordance with a preferred embodiment of the invention that will be illustrated herein, the problem carrying a spare tire on a vehicle is addressed. The present invention permits a spare tire to be carried on the rear of a vehicle while not interfereing with the functionality of the rear closure of the vehicle and other components situated at the rear of the vehicle, such as a trailer hitch.
The present invention provides an apparatus for carrying the spare tire for a vehicle, the apparatus comprising: a swing arm member pivotably attached to the vehicle at one end; a pivot arm pivotably attached to the swing arm and supporting a spare tire for movement between raised position wherein the spare tire is located above ground and lowed position wherein the spare tire contacts the ground; a tire support fixedly connected to the pivot arm for mounting the spare tire; a mechanism which secures the pivot arm to the swing arm once the pivot arm is substantially parallel to the swing arm; a mechanism which secures the swing arm so that it will not pivot.
In another aspect, the present invention provides an apparatus for carrying the spare tire for a vehicle, the apparatus comprising a tire support for mounting a spare tire including at least one lug for securing the tire to the tire support and material extending past the lug which supports the tire so that the tire may be rotated to align the tire with the lug.
For a better understanding of the present invention, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, and the scope of the invention will be pointed out in the appended claims.